Like meat-eating, pet ownership is nowadays encouraged by a vast industry; the pet insurance sector alone is said to generate more of Britain’s GDP than fishing does. The production of pet food, provision of veterinary services and breeding the creatures are big businesses, all with an interest in promoting the alleged benefits of owning a furry friend.

There’s something rather astonishing about humans, especially those concerned about the environmental impact of our species on other ones, cheerfully possessing animals that are the results of generations of selective breeding and which exist purely to give their owners pleasure. It all sounds a bit like a ghastly dystopian sci-fi fantasy.Brian Hughes Cheltenham

• George Monbiot’s article inspired me to cook vegetable curry for dinner, but surely limiting population growth is as important as changing our diets in order to conserve human and other life forms on this planet?Hazel SutcliffeHolmes Chapel, Cheshire

This earlier article, reporting on a study published in Environmental Research Letters, compares the results of different courses of action. By far the greatest impact is having one fewer child, which equates to saving 58 tonnes of CO2 for each year of a parent’s life. This takes into account the child’s total life, and that of his or her descendants, in proportions described in the article. In comparison, eating a plant-based diet would only save 0.82 tonnes. There is a graphic in the article which shows this very dramatically.

Therefore, while the measures proposed by George Monbiot are helpful, their effect will be minimal compared with reducing our progeny.Roger PlentyStroud

• George Monbiot is correct that the way we currently produce meat is inherently inefficient. But we don’t have to give up meat entirely. Instead, we should make meat from plants and through tissue engineering – no animals required. Plant-based meats are already available in grocery stores. From Moving Mountains’ new “bleeding” burger to Vivera’s groundbreaking steak, there has never been a better time to switch to plant-based meat, which is vastly better for the animals, our health, and the planet. For those who want to eat meat that actually came from animals, meat grown directly from cells, called “clean meat”, is coming soon; like plant-based meat, it will vastly ameliorate the harms spelled out by Mr Monbiot. Bruce FriedrichExecutive director, The Good Food Institute, Washington DC

• While the discovery of meat traces in vegan and vegetarian ready meals (‘Meat found’ in vegan food, 9 June) will have come as a shock to many – including, I suspect, those producing these foods – the reality is that we live in a world where animals are routinely killed by the billions for their body parts, and worrying about trace amounts of animal-derived foods in vegan products won’t help them. It’s no different from eating a veggie burger at a restaurant that also serves meat or off the grill at a friend’s barbecue – there’s always a chance of cross-contamination. What we have to remember is that the packets of bacon and beef sold by supermarkets are composed 100% of dead body parts – so those are the products we should avoid if we want to help animals.

Eating vegan isn’t about “perfection” or a quest for personal purity – it’s about achieving real change for animals suffering in the food industry. Choosing a vegan burger over a meat-based one is a win for them, the Earth and one’s arteries, and Peta offers a free vegan starter kit for anyone wanting to make the shift towards a more compassionate way of living.Jennifer WhitePeople for the Ethical Treatment of Animals